According to local security officials, the incident took place late on Monday in Gardez, the capital city of Paktia province.
Provincial police chief, Gen. Zalmai Orya Khel said the blast took place in a crowded market after explosives planted near the shops went off.
Gen. Orya Khel confirmed that 24 people, all civilians were killed and 23 others were injured.
Officials in provincial hospital also confimed that 4 dead bodies were taken to hospital along 23 othes who were injured in the blast.
Dr. Haya Gul Paktin, head of the provincial hospital said a number of those injured in the blast are in critical condition and there are fears that the death toll could rise.
He said a number of women and children were also among those injured in the explosion.
No group including the Taliban militants has so far claimed responsibility behind the incident.